.button {
    border-style: solid; 
    border-color: black; 
    margin: 5px; 
    padding: 3px; 
    background-color: lightskyblue; 
    text-align: center; 
    vertical-align: middle;
    display: block;
    width: 250px;
    cursor: pointer;
    cursor: hand;
}

.invisible {
    display: none;
}

.result {
    border-style: solid; 
    border-color: black; 
    margin: 5px; 
    padding: 3px; 
    background-color: aliceblue; 
    display: block;
}
